Qassem Safari; Mohammad Reza Malek
Abstract
Extended Abstract
Introduction
Earthquake is one of the most frequent natural hazardsannually leading to numerous human and economic losses. Both in the planning stage and after the earthquake occurrence in the relief phase,findingappropriate sites for temporary housing is considered to be one ...
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Extended Abstract
Introduction
Earthquake is one of the most frequent natural hazardsannually leading to numerous human and economic losses. Both in the planning stage and after the earthquake occurrence in the relief phase,findingappropriate sites for temporary housing is considered to be one of the most important issues in reduction of damages caused by earthquake. Temporary housing, especially in a crisis situation is always accompanied by elements of uncertainty. Hence, definitive and classical approaches normally do not lead to acceptable results without involving elements of uncertainty. Although using methods based on fuzzy logic and fuzzy set theory are conventional and appropriate for uncertainty modeling, these methods also have their own disadvantages. For an instance, they require a certain and definitive membership function for each parameter. Moreover,fuzzy theory cannot describe verbal variables related to doubt and hesitation.
Temporary housing is always accompanied byuncertainty.Thus, fuzzy theory cannot lead to reliable results in this regard. However, in case sufficient information is not obtained using fuzzy theory, intuitionistic fuzzy logic isconsidered to be an appropriate solution for this problem and uncertaintymodeling. Despite various applications of intuitionistic fuzzy logic in uncertainty modeling, few researches have focused on this method.
Materials & Methods
Designing a qualitative model based on human knowledge requires a rule-based inference system, which is called an Expert System. This system consists of several parts. In the knowledge-based part, data and a set of rules, which are based on expert knowledgearesavedin the form of logical sentences. The input of this system is a set of numbers fuzzified in the inference engine by a set of fuzzy rules. Then,defuzzification is performed to map the fuzzy set and reach a certain point. In other words, the outputs must be readable and easy for the users.
The present study takes advantage of fuzzy and intuitionistic fuzzy approaches todetermine optimal sites for temporary housing. Furthermore, determinant factors of danger and safety followinganearthquakeare used to identify safe places for sheltering in such situations. The present study has applied layers of faults, hospitals, emergency and medical centers, fire stations, parks and green spaces, and roads as determinant factors. New spatial layers were produced for each ofthe aforementioned layers using distance and other similar functions. Then, trapezoidal functionwas used to determine membership and non-membership function of each layer in both fuzzy and intuitionistic fuzzy methods. Membership functions obtained from these methods are different in that they assign different membership values to the pixels surrounding the layer. Following the definition of membership and non-membership functions for each layer in both methods, temporary accommodation maps were obtained using the classical fuzzy as well as intuitionistic fuzzy methods.
Results and Discussion
The results obtained from these two methods were not identical. The main reason for this difference is that they treat data uncertainty differently. Furthermore, the results of membership and non-membership functions inintuitionistic fuzzy are not complementary. This provides us with a powerful tool for interpretation and, of course, decision making about the study area. As the first case, membership and non-membership degreesequal zero and one implying that the membership degree equals one and the non-membership degree equalszero. This occurs when the method identifies the area as quite appropriate for temporary housing after the earthquake. In this case,results are determinative, and data can be used in the area. In the second case, membership and non-membership degreesare low, which occurs in areas lacking enough information. It implies that more information is neededin such areas for decision making. The third condition takes place when both membership and non-membership degrees equal 0.5. In such a case,it can be conclude that either the stated variable belongs to the area with a membership degree of 0.5, or the variable doesn’t belong to the area with a non-membership degree of 0.5. In the fourth condition, the membership degree is high and the non-membership degree is low. In this case, the results can be trusted and used in decision-making. The fifth condition is in contrast with the fourth case. It occurs when the non-membership degree is high and membership degree is low. Under this condition, it can be concluded that the results are not reliable.
Conclusion
The proposed method and model were implemented in the second district of Tehran. According to the results, it can be concluded that the proposed approachperforms better than theclassical fuzzy approach, especially in the presence ofuncertainvariablesand lack of adequate data.
Mehrdad AhangarCani; Mohammad Reza Malek
Abstract
Extended Abstract
Introduction and Objective
Road traffic accidents impose numerous social, economic, and cultural costs upon various societies, especially developing countries. Identification of accident blackspots is a method proposed to deal with car accident risks. Among various events associated ...
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Extended Abstract
Introduction and Objective
Road traffic accidents impose numerous social, economic, and cultural costs upon various societies, especially developing countries. Identification of accident blackspots is a method proposed to deal with car accident risks. Among various events associated with transportation network, road traffic accidents play a significant role, because of their specific features, including high frequency, high intensity and the chance of direct involvement of all members of the community.This problem is more conspicuous in developing countries such as Iran. The present study aims to identifyaccidentblackspotsand to prepare risk map for road trafficaccidents in Babol city using volunteered geographic information.
Materials and methods
According to the characteristics of the study area, the present study takes advantage of criteria such as distance from population centers, proximity to city squares, distance from footbridges, and proximity to road intersections to identifyaccidentblackspotsand a prepare risk map for roadtraffic accidents in Babol city. Accident blackspots detected by volunteered geographic information, along with the criteria determined by applying analytic hierarchy process (AHP) and analytic network process (ANP) were compared in a pairwise manner, and their respective weight was calculated to showtheir specific level of impact. Ultimately, a risk map was produced for the risk of road traffic accidents obtained from each method. In order to evaluate the accuracy of the identified accident blackspots obtained from volunteered geographic information, as well as the accuracy of susceptibility maps, ROC curve and Kappa Coefficient were applied to police official records.
Results and Discussion
According to the findings, Jame Mosque shopping center, Shahabnia shopping center, intersection of Farhangstreet and Velayat square were identified as the most accident-prone areas in Babol city. Also, among the prespecified criteria, distance from population centers and distance from intersections are considered to be the most important criteria, respectively. Results obtained from the evaluation criteria indicatedhigh accuracy of volunteered geographic information, and thus it is concluded that this kind of information can be effective in determining the accident blackspotsinBabol city. Also, the ANP method works better than AHP method in preparing the risk map of accidents.
Conclusion and Future works
Due to the large number of road accidents, especially in developing countries,the issue of accident blackspotsand providing a risk map for road trafficaccidents are an essential part of roads safety. In the present study, volunteered geographic information was used, along with multivariate decision-making methods of analytic hierarchy process (AHP) and analytic network process (ANP) to identifyaccident blackspots based on number, causes and severity of accidents and to develop a risk map for driving accidents in Babol city. Moreover, the criteria of distance from population centers, proximity to the city squares, distance from the footbridges, and adjacency to intersections were used to determine accident blackspotsand to prepare a risk map for driving accidents in Babol city. According to the results, Jame Mosque shopping center, Shahabnia shopping center, Farhang intersection and Velayat square were identified as the most accident-prone points in Babol city. Also, distance from population centers and distance from intersectionswere identified as the most important criteria, respectively. Evaluation criteria demonstrated that volunteered geographic information can be effective and accurate in determining accident blackspotsinBabol city. Also, the ANP method worked better than AHP method in preparing the risk map of driving accidents. The method proposed in this study to identify accident blackspots and preparedriving accidents risk maps can be generalized to other areas. Basedon the characteristics of specific routes, other criteria such as arc radius, longitudinal slope can alsobe used. It is also suggested that the results of other methods used for investigation ofaccidentblackspotsand production of risk maps based onvolunteered geographic information (VGI) are compared with the results of the present study.
Sara Haghbayan; Mohammad Reza Malek
Abstract
Extended Abstract
Introduction
Recently, different volunteered Geographic Information (VGI)databases and websites have been launched for a variety of purposes and different groups of users. Various groups and portals collect and share these data. Thus, there is a huge potential for the participation ...
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Extended Abstract
Introduction
Recently, different volunteered Geographic Information (VGI)databases and websites have been launched for a variety of purposes and different groups of users. Various groups and portals collect and share these data. Thus, there is a huge potential for the participation of millions of people who can act like remote sensors and share their data with other members of the group without any cost.Therefore,diffrent users with different skill levelscan provide spatial data through personalized measurements. Various research perspectives have shown that sometimes Volunteered Geographic Information can compete with business data.The present research seeks to solve the problems in searching and finding properties, and describe indoor space using visual components in web-basedplatforms. The impact of spatial information on satisfaction of residentsortheir problems has made this research especially important.Most of related studiessought to provide models for estimationof prices, and the impact of environmental factors on the price of real estates. They also have endeavored tocreate websites for residential real estatesearch with an emphasis on descriptive information.The present research seeks to describe indoor space of residential real estate using spatial tools.In this regard, criteria like height, dimensions, topological relationships, shape, color, geographic location, and directional relationships are considered.Description of residential properties’ indoor space requires information in both spatial and descriptive dimensions. Due to the especial potential of Geospatial Information System in the simultaneous visualization of spatial and descriptive information, spatial analysis was used in the present study.
Clearly, any research is performed based on a set of presuppositions. Particularly when we seek to theoretically investigate a process like modeling or design an information system, the work scope will be very wide and serious challenges will occur without proper assumptions. The present study assumes equal spatial perception, verbal expression and visualizationabilityin all people. It is also assumed that all estate visitors havecell phones equipped with cameras and Global Positioning System and their response to qualitative relationships is better than that of quantitative relationships. Moreover,real estateis used as a synonym for apartmentin this research.
Materials & Methods
Considering the critical role of the ordinary users and the fact that survey processes are usually expensive and time consuming, volunteered spatial information environments are the most appropriate way of gathering people’s spatial perception. Not only these environments are rather easy to use, but also they simultaneously receive up-to-date information from the participant and provide them with appropriate services according to their status.
After modeling and designing, the proposed systemwas implemented in Visual Studio 2012 platform using ASP.NET framework andC#language. Server Structured Query Language (SQL) Database 2012 was usedto save spatial information. Tehran District 14 (longitude: 51.46207, latitude: 35.66905) was chosen as the study area and data collected from several residential properties was recorded in our database.
Results & Discussion
Results indicate more than 65 percent conformity between the mental image generated using the proposed method and the reality. Users’ satisfaction with the proposed model was compared with their satisfaction with three popular Iranian sites, and a foreign site regarding. The impact of tools applied in these websites was also investigated. Results indicate 78.78% satisfaction with the proposed system, which is the highest level of satisfaction as compared to other studied websites.Moreover, compared to other toolsinvestigated in the present study,virtual tours and thenmaps are more in visualization.Sincespatial perceptions depends on various parameters such aspersonal interests, spatial dimensions, gender, age, education, culture, and fields of study, different groups were investigated in the present study.
Conclusion
Using information collected inVolunteered Geographic Informationenvironments, ordinary people can share information and use each other’s experiences and opinions. This improves their knowledge level and results in a better understanding of the advantages and disadvantages of different real estates. Due to increased knowledge level, people will not select undesirable properties. This will create a competitive market and increase designers and engineers’attention to indoor space, which will consequently increase ordinary users’welfare.
Sepehr Honarparvar; Mohammad Reza Malek
Abstract
Introduction
In recent decades, rapid climate changes in the Middle East have led to the rapid growth of drought phenomenon. Given the recent observations and surveys in the countries of the region, the rate of evaporation of surface water has increased. In addition, water consumption has increased ...
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Introduction
In recent decades, rapid climate changes in the Middle East have led to the rapid growth of drought phenomenon. Given the recent observations and surveys in the countries of the region, the rate of evaporation of surface water has increased. In addition, water consumption has increased dramatically in recent decades due to various causes, including industrial and agricultural development and population growth. Apart from the natural causes, the lack of proper management and planning of water resources is one of the main reasons for drought occurrence in the country. It’s obvious that every program needs reliable and updated information to help planners make decisions. Therefore, information onthe volume changes and the amount of water is of great importance in the management of the limited water resources. This information is usually obtained using conventional methods of remote sensing, surveying and photogrammetry which require significant amount of time and money. On the other hand, obtaining information from people is very beneficial due to the high speed, low cost of preparation and high volume of shared information. Volunteered Geographic Information provides an environment for the acquisition of spatial information from ordinary and expert people.Recently, many researcheshave been carried outon geography, natural resources and geosciencesin relation to the voluntary applications of spatial information in crisis management, and it has been proved that these data are suitable for managing long-term and short-term crises. Regarding the water management in particular, researches have been carried out on collecting water pollution information through sharing the location and the type of water pollution. The issue of drought in water resources has not been taken into consideration in this category of investigations.Another category of the researches is about the type of architecture used to obtain popular information from the volunteered spatial information, while the quality of this information has been ignored. In another category of the researches, users identify and report the rate of changes in water resources using remote sensing and aerial images but, this method is indirect and does not share information instantaneously and directly.
Materials and methods
The aim of this paper is to design and develop a Volunteered Geographic Information system for receiving and updating drought information on natural water resources. To do so, users send the information on water volume and its changes as well as the location, to the drought information spatial database. The case study of this paper is the water resources of the rivers and lakes of the TashkBakhteganMaharloubasin. TashkBakhteganMaharlou is a basin region in the province of Fars in Iran,and the reason for choosing this basin as a case study isthe abundance and diversity of water resources in the area. A Web-based mobile application has been developed to receive the popular information of water resources. Users can share information based on the level of access. This level of access is determined based on the level of users’ expertise and occupation relative to water sciences. In order to implement this system, a client - server architecture was employed, in which SQL Server was used as the updating and managing system of the spatial database, ArcGIS Server as a spatial server, WCF Service to receive thematic information, JSON as the format of exchanging data and Android as the client’s development language.
Discussion and results
In order to evaluate this system,the spatial accuracy, descriptive accuracy and the integrity of the Volunteered Geographic Information were measured. After the evaluation, a spatial accuracy of 12.5 meters, a descriptive accuracy of 67%, and the integrity of 75% were obtained. Moreover, 80% of the Volunteered Geographic Information hadan area of more than 1 Hectares,representing the interest of the users in sharing lakes with wider areas. Meanwhile, 65% of the Volunteered Geographic Information has a density of 27 lines per Hectare, indicating that people are willing to share rivers with denser branches.
Conclusion
Since the datawas collected by smartphones’ GPS,this amount of spatial accuracy was predictable. Descriptive accuracy obtained is relatively low due tothe ambiguity in the naming of received data. The high integrityindicatesthe capability of the system in updating drought spatial database over a short period of time. Therefore, it seems that the Volunteered Geographic Informationon drought is generally acceptable for completing the water resources database and for the management and making decisions on the planning of conserving water resources in a short time with low cost.
Mohsen Mehrabi nejad; Mohammadreza Malek
Abstract
Extended Abstract
Introduction
Initially, researches were conducted on the positioning inside and outside of the building separately, and separate methods have been presented to determine the position inside and outside the building. But today, they are seeking methodswithout borderfor the ...
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Extended Abstract
Introduction
Initially, researches were conducted on the positioning inside and outside of the building separately, and separate methods have been presented to determine the position inside and outside the building. But today, they are seeking methodswithout borderfor the positioning that can be used to conduct both indoor and outdoor location. Today, location-based services are one of the most widely used programs in mobile tools, but there are two obstacles that prevent these services from using their full potential. First, the location of individuals is not accessible at all points. The second obstacle is the lack of an integrated service to determine the position. The second obstacle has been addressed in this research. Users tend much to do the integrated positioning in internal and external environmentsusing their mobilephone devices. There are various methods for positioning in interior and exterior environments with respect to their characteristics. Therefore, in order to use the appropriate method for positioning in any environment, first there is a need to know the environment.
Materials & Methods
In this research, the definiteexpert system was used for the detection of the environment. In the definite state, the existing space is divided into two internal and external parts. The internal space is the internal parts of the building and the rest of the spaces are known as the external space. First we specify the various factors in the detection of the environment, and then, to establish the knowledge base by definite method, different modes of the combination of factors were taken into consideration and finally, the results of each method were investigated. In order to detect the environment, four factors of light, numbers of satellites, accuracy and waves of wireless network were used. The expert system was used for decision-making.Regarding the number of satellites, it can be said that since receiving the waves of satellites in internal environments is difficult and the communication of the receiver with a number or all of the satellites is interrupted, therefore, it is expected that the number of satellites whose waves are receivable inside the building to be less than the satellites which are located on the horizon of that region.Another one of the factors of environment detection, the satellite signals are received by the receiver and the positioning is done. Due to the presence of the building and obstacles in these areas, the positioning is done with low accuracy, therefore, given that the accuracy of positioning in external environment is higher than that in internal environment, the detection of environment can be carried out with respect to the measurement of the positioning accuracy. One of the factors that indicate the accuracy of positioning is the DOP value. The accuracy of the two-dimensional positioning is determined by HDOP which indicates the accuracy of planimetric positioning. Given that the accuracy of positioning using GPS in the external environment is better than the internal positioning accuracy, therefore, the HDOP values in the internal environment will be higher than external environment.
The power of received waves of wireless networks depends on the receiver’s distance from the transmitter. The more the receiver is close to the transmitter, the greater will be the power of the received waves. Since the wave transmitters of the wireless networks are usually installed inside the building, therefore, the receiving power of these waves inside the building will be higher than the outside. Therefore, it is possible to perform the detection of the environment by measuring the receiving power of these waves.
Researches show that the amount of light for indoor environment is generally much lower indoor than open or semi-openspaces, even in cloudy and rainy days. This is true even when the light sensor is rotated downwards. Its main reason is that the intensity of the sunlight is in the visible spectrum which is usually much higher than lamp light. Moreover, the light sensor has the ability to detect the light in the invisible spectrum like infrared and ultraviolet. When the sunlight and artificial light appear to be the same, the bright flux of the sunlight is much higher than the artificial light sourcesthroughout the day, therefore, the indoor environment of the building can be different from the outdoor in terms of the light intensity. This research was implemented in the mapping department of KhajehNasir University. The outer area of this university was considered as the outdoor environment and the corridor of the mapping department building’s ground was studied as the internal environment.
Results & Discussion
To create a classical expert system, the thresholds of each of the factors were determined by the measurements done. Then, for different modes, the necessary rules for detecting the environment were defined and the knowledge base was formed. Finally, after the formation of the database in different parts of the study area, the system was evaluated and its results were presented. We divided the study area into two internal and external environments.To evaluatethe results, we were deployed in each of the aforementioned places4 times, and we matched the environmentdetectionby the system with the reality and evaluated the amount of system accuracy.
Conclusion
The results of this method show that the best result has been obtained when the light, accuracyandthe waves of wirelessnetwork were used. 92% of the detection of environment has been carried out correctly. The results also showed that in some exterior area, the detection of environmentwas associated with mistakesdue to the presenceof false ceilings and insufficient light. In the case of the accuracy and the number of satellites, in the external areas where there were high walls and satellite waves were not well received, the detection of environment was not done correctly.
Seyyed Vahid Razavi Termeh; Mohammad Reza Malek
Abstract
Extended Abstract
Introduction
Over time, spatial data has evolved from paper maps to Web GIS through digital mapping and finally to the current generation of GIS. Although this new interface has enhanced user’s insights about spatial information, it still needs more tangible interface that ...
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Extended Abstract
Introduction
Over time, spatial data has evolved from paper maps to Web GIS through digital mapping and finally to the current generation of GIS. Although this new interface has enhanced user’s insights about spatial information, it still needs more tangible interface that can be usable to the public and enhance human interactions with the environment and spatial objects. Combining real and virtual worlds, Augmented Reality (AR) systems can make more tangible experience with real world objects. These activities relies on the dynamic working environments. Therefore it is important to consider the users environment and its changing through context-awareness. Context-awareness is any kind of information about user’s status and its estimation allows to integrate the context with the happening changes. AR is a combination of real vision with virtual content in real–time and acts as an interface to increase user insight of the real world and interaction with it. With increasing information in the AR, the usefulness and readability of information decreases and the details and their display should also be subject to certain conditions. To overcome this problem, we offer the combination of AR with context-awareness. Hence, in this study, The AR representation varies according to the user’s context. The increasing use of sensors, their hardware and software enhancements, and growth and development of communication networks have led to development of context-aware computing. Context-aware computing is rooted in processing anywhere and anytime, and aims at understanding environmental changes in computer systems so that computers can understand and respond to their environment. The small screen, low bandwidth, interaction problems, and user’s quick need to obtain response from service have driven services to provide information based on users and their environments. Nowadays, in most location planning applications, they try to use directional data besides location data. By using this information, better interaction and information are provided to user. The activities performed depend on user’s dynamic work environment, so by using context-aware knowledge, the environment and user environment changes receive more attention. The output of old programs was based on specific input and did not consider context change.
Materials & Methods
By increasing the amount of realistic information, simultaneous provision of all information will not only reduce the usefulness and readability of information, but also details and their presentation. In order to overcome the problem, we have used a context-aware augmented reality that displays the necessary information according to actual increase in user’s context. Specially in the domain of spatial services, given the massive amount of the available information and simultaneous provision of data in real-time due to small display of associated equipment make visual distraction for user, so by using context-awareness, useful and proper information can be provided to the user. Having the vulnerability maps, specifically about buildings in the region of interest is a necessary requirement for any rescue and relief teams after earthquake. Due to the lack of immediate access to earthquake vulnerability maps, it is necessary to provide an intelligible context information system for displaying vulnerabilities of building with the help of augmented reality. In general, any type of navigation issue, information about building vulnerabilities to select safe paths or temporary accommodation is required. In order to implement such information system, three contexts, i.e. distance, direction and time for presenting information in augmented reality was studied. To this purpose, after zoning vulnerability caused by earthquake in Tehran, Donyaye-Noor business complex was used as the case study and information system was considered with three contexts for given site. In order to evaluate the presented system, our context-aware augmented reality system was compared with an augmented reality system alone.
Results & Discussion
Results of evaluation show that combination of augmented reality and context-aware can reveal suitable information by considering the user context, while data presentation in augmented reality is monotonic and there is no dynamism in changing information display. The results of evaluating combined augmented reality system with context-awareness compared with augmented reality alone show that context-aware augmented reality system is more active and always reveals more adopted information to the user regarding environmental dynamics. While information is uniform and does not change in augmented reality.
Conclusion
Using the context-aware spatial information system, the user can take different decisions under different circumstances or gain extra information about other context such as time, velocity, acceleration. To better understanding augmented reality, certain graphical forms can be used. Displaying vulnerability by augmented reality can be a tool for ordinary users or specialists in the field of urban design and management, without the need for mapping and map reading knowledge in managing important centers and building in low-risk areas. The results of integrated system evaluation from various users indicate the system’s performance is superior to augmented reality system alone.
Mohsen Ahmadkhani; Mohammad Reza Malek
Abstract
Extended Abstract
Despite of widespread usage of Global Positioning System (GPS), this system is considered inefficient for indoor areas. Although the most prominent positioning system is Global Positioning System, this system uses some electromagnetic waves which are unable to pass thick obstacles ...
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Extended Abstract
Despite of widespread usage of Global Positioning System (GPS), this system is considered inefficient for indoor areas. Although the most prominent positioning system is Global Positioning System, this system uses some electromagnetic waves which are unable to pass thick obstacles such as concrete roofs and trees [1]. Thus, it cannot be considered as a robust infra-structure for indoor positioning purposes. Since, other signal networks like Wireless Local Area Network (WLAN) can be an appropriate alternative for indoor spaces. In addition, widespread usage of mobile smart instruments has provided the possibility of ubiquitous system’s development.
Several methods have been proposed to obtain indoor positions which are generally based on received radio waves from fixed points. Time of Arrival (TOA), Time Difference of Arrival (TDOA), Angle of Arrival (AOA) and Location fingerprinting can be used in this case. It is noteworthy that some of these methods are not really appropriate for indoor areas which maybe contain complex structure [2]. Time of Arrival, Time Difference of Arrival and Angle of Arrival methods use triangulation techniques so direct lines of sight are desired for them. And also acquisition of accurate time and angle of received signal without professional instruments, which are usually expensive, sounds almost impossible. Furthermore, for most of indoor areas such as commercial centers and museums direct line of sight is rarely available and signals are likely to be affected by multipath phenomena [3].
In recent years methods based on Inertial Measurement Units (IMU) have been proposed and programmed [4], [5]. These methods which are usually called Pedestrian Dead Reckoning (PDR) often employ sensors such as Gyroscope, Accelerometer and Magnetic sensors to obtain the position of the client [6]. It can be regarded as an important limitation along the objectives of the Ubiquitous systems. Such systems are restricted to clients equipped by platforms having these expensive modern sensors. Therefore, the methods using WLAN signals are usually preferred for location based services.
WLAN Fingerprinting can be regarded as a most appropriate technique that uses signal strength as an identification parameter, which can be simply obtained. Furthermore, fingerprinting does not have any special infrastructure to establish and it can be conveniently laid out. In order to apply this method there are several ways to recognize the pattern of signals received from active transmitters. Stochastic method, Artificial Neural Network and K-Nearest Neighbor methods are some of classic pattern recognition techniques [7] that were investigated in this study. In this article these three methods were scrutinized and relatively compared, eventually an enhanced method has been offered. After using several data sets in order to assess the pattern recognition techniques, the proposed method got the first rank of the accuracy and also other techniques were ranked based on the accuracy.
One of the most important differences between indoor positioning systems might be utilizing of various algorithms to recognize the spatial pattern. In this study, three popular classic methods including Probabilistic algorithm, Nearest Neighbor and Artificial Neural Network were investigated. The flowchart presented in Figure 1 has depicted the major steps of the study.
Figure 1. The flowchart of the study.
This study focuses on Nearest Neighbor in Signal Space method as the most accurate method among all and tries to enhance the output accuracy of the method. NNSS Method computes the difference between received signal strength in a point from each transmitter and the received strength of that signal in the rest of the sample points (Equation 1).
(1)
Where Sij be jth sample point of the database from ith transmitter and Si received signal strength from ith hotspot in online phase and also for m hotspots and n sample points, i= 1,2,…,m and j=1,2,…,n [8].
By applying this formula, the most likely sample point as the location of the observer can be obtained. Since the number of sample points in the design of the model in offline phase is limited and the distance between two adjacent sample points is constant in the whole model, the accuracy might be affected. Regarding these limitations, in order to increase the output accuracy of the system, the medium of first and second candidate location points was proposed as the position of the user. After applying this change, the highest accuracy was acquired (Figure 4). The study area was the third floor of the building of Geomatics faculty of K.N.Toosi university of Technology (Figure 2). For this building with dimensions of 70×14 meters, totally 6 hostspots with reasonable distribution, covering the whole area, were taken into account. The best distance between each adjacent pair was 0.9 m and for each sample point four directions were observed and recorded in to the database and also JAVA programming language was chosen to develop the user friend software. Figure 3 depicts an instance of the database.
Figure 2. Plan of the study area.
Figure 3. A part of the produced database.
In order to evaluate the accuracy of each method, observations in the online phase were categorized in 6 separate classes containing 10, 20, to 60 obser-vation in each class. Based on the output results of the system, although the accuracy of Artificial Neural Network raised up to 2.7 m by increase in the number of observations, it showed the worse accuracy among all methods. Probabilistic and KNN methods with final accuracy of 1.8 and 0.9 meters respectively were more accurate than ANN. Our extended Nearest Neighbor method was the most accurate method almost in all sets of observations. In the first observation class, ANN with 3.6 m, KNN and Probabilistic methods with 2.7 m were not really reliable to locate the position of the user, however, extended KNN with 1.5 m seemed more acceptable than the rest of methods (See Figure 4).
Figure 4. The behavior of accuracy trend in all methods in the considered sets of observation.
Farzad Foroozani; Mohammad Reza Malek; Ali Esmaeily
Abstract
Abstract
The Distribution networks are the most important part of the utilities that distribute electrical energy to the consumers. Problems with location-referenced information such as inaccuracy, inability to control information, and lack of rapid access to information are considered as technical ...
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Abstract
The Distribution networks are the most important part of the utilities that distribute electrical energy to the consumers. Problems with location-referenced information such as inaccuracy, inability to control information, and lack of rapid access to information are considered as technical problems. The complexity of updating information, the complexities related to information storage and wearing out are no exception to this rule. Existing technical problems and the failure to use the new systems in the relief issue will prolong the duration of the blackout. The purpose of this research is to design and implement a context aware spatial information system for providing a series of services such as routing, map displaying, and the provision of distribution network information in the field of urban electricity distribution incidents. Urban electricity distribution networks consist of various parts and equipment. The rescuer determines the type of failure due to available and accessible network information. The failure type is considered as the user's environmental context, and the location of the rescue vehicle is considered as the location context. Therefore, the context in this study are classified into two general categories of position and network context. Finally, the implementation and testing of a designed to help managing the urban electrical distribution networks was studied which resulted in 80% satisfaction.
Soroush Ojagh; Ali Asghar Ale sheikh; Mohammad Reza Malek; Mohammad Fallah Zezoli
Abstract
Nowadays, we are observing a huge revolution in the use of mobile equipment in all aspects of human life. They greatly facilitate our daily life by their numerous capabilities such as powerful processors and various embedded sensors. Reviewing the history of Geographic Information Science (GIS),one can ...
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Nowadays, we are observing a huge revolution in the use of mobile equipment in all aspects of human life. They greatly facilitate our daily life by their numerous capabilities such as powerful processors and various embedded sensors. Reviewing the history of Geographic Information Science (GIS),one can clearly recognize that real time spatial processes have been the most important concern over the years. On the other hand, data gathering phase is the most time and cost consuming phase in most practical projects. Using traditional way to perform data gathering phase, not only causes some noticeable problems such as: the difficulty of carrying paper maps, inevitable human made mistakes; but also create a deep gap for hitting the main goal of performing a real time spatial process. In this study, by developing a context-aware mobile information system that takes advantage of distributed architecture, we try to deal with those problems. Our ultimate goal is to replace our developed system by traditional methods for gathering spatial and descriptive data about nuisance jobs in Kermanshah, Iran. We assess and compare our system with traditional methods by comparing their results for collected data in 4 districts in a city by different groups of users. Statistical tests prove our developed system has more reliability and efficiency compared with traditional methods. At the end, the tendency of about 92% of user to use our system compared with traditional methods is another measurethat indicates our success in achieving the ultimate goal of this study.
Hamid Bagheri; Mohammad Reza Malek; Ali Esmaeilie; Mahdieh Ghodsinejad
Abstract
In recent decades, the limitation of urban water resourcesand the wear and tear of transmission lines, the short life span of water network elements, the increasing fracture of pipes and the high losses of networks have led to increased economic and social costs in the utilization of distribution network ...
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In recent decades, the limitation of urban water resourcesand the wear and tear of transmission lines, the short life span of water network elements, the increasing fracture of pipes and the high losses of networks have led to increased economic and social costs in the utilization of distribution network infrastructures. Lack of information, oldness of network data and the absence of spatial information system for incidents is one of the major problems facingmanagement of water transmission networks. Although the provision of such data is supervised by government agencies and is subject to certain standards, the problem of shortage, defect and delay is still evident. One of the solutions proposed to solve this problem is the use of citizen participation in the provision of spatial data. Using the Volunteered Geographic Information environments and the Information ofnative people can be a quicker and less costly method to update the maps. In the context of the present paper, Volunteered Geographic Information environment was used to accelerate the process of servicing in urban water network in cases of problems such as water pipes leakage, pipes rupture, illegal excavations, etc. After modeling and designing the proposed system, it was implemented in the Visual Studio2012 environment and in the ASP.NET framework using C# language.The SQL Server2012 database and GeoDataBase were used to store spatial and non-spatial information, respectively. ArcGIS Server10.2 software was used to enter the maps on the system. At the end, according to the survey resultsobtained from people, about 80 percent of participants in the inquiry were satisfied with the designed system. Also, based on a survey results obtained from four experts of water organization, three of them were satisfied with the design of such a system.
Javad Saberian; Mohammad Reza Malek
Abstract
Mobile devices are widely used for providingpeople with needed information anytime and anywhere. One of themost important mobile applications is related to the navigation andother GIS capabilities. The development of mobile applications needs tobe adapted with the special features and limitations of ...
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Mobile devices are widely used for providingpeople with needed information anytime and anywhere. One of themost important mobile applications is related to the navigation andother GIS capabilities. The development of mobile applications needs tobe adapted with the special features and limitations of thiscomputing environment. Looking in this direction, we present a context-aware mobile map representation which used the dual graph ofstreet networks for automatic simplification and generalization of streets invarious contexts. For this purpose, after the introduction and selectionof context factors, the degree of dual graph nodes areused for automatic generation of maps with fewer details. Wewill show that we could increase the capability and efficiencyof mobile GISs by using dual graphs, because by usingthat, the structure and the topology of streetnetwork could be maintained in generalization process.The proposed approachis validated by a case study applied to a regionof Tehran city. The case study clearly showed the benefits of usingdual graphsin mobile map applications.
Nagmeh Neisany Samany; Mahmoud Reza Delavar; Mohammad Reza Malek
Abstract
Navigation is one of the most important daily activities of individuals in an urban environment. The spatial information systems of the user guidance are the most common services which guide people to navigate the various routes with different goals.The main challenge of such systems is providing context-aware ...
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Navigation is one of the most important daily activities of individuals in an urban environment. The spatial information systems of the user guidance are the most common services which guide people to navigate the various routes with different goals.The main challenge of such systems is providing context-aware navigation information. The location, time,and the identifier of the individual person are among the primary contexts and the other related contexts are modeled based on these contexts. The present paper attempts to model the spatial-temporal communication of the moving user based on the identifier of the individuals. So that it covers all spatial communications (topologic, metric and directional) in time dimension andtakes the characteristics of the user and the related contexts into consideration. In this regard, the proposed model utilizedthe advantages of Allen’s Multi-Interval Algebra (MIA) and dynamic Voronoi-based Continuous Range Query (VCRQ), and introduceda new method by following the large calculus principles and the existing customization methods. The designed model (MIA25) was implemented in a software applicable in mobile systems. The evaluation of the implemented model in the tourist’s navigation scenariointhe regions 3, 6, and 11 of Tehran municipality was carried out based on 3 parameters of accuracy, runtimeand users’ satisfaction. These three regions were selected as the case study area. In order to test the accuracy of the model, the designed software was iterated 100 times in three different routes in the study area by three different tourists at three time intervals with two different average speed. Then, the recognition of each one of the textures existing on the way, was examined by the one-way binomial approximationwith 95% of confidence level over 100 iterations. Also, two indices of correctness and recall were used to evaluate the recognition of the textures through the entire route. The results of implementation and evaluation of the model based on three parameters of accuracy, runtime and users’ satisfaction demonstrate the efficiency of the proposed model in an urban context-aware navigation system.
